Effect of Metabolic Syndrome on Left Atrial and Left Ventricular Deformation and Atrioventricular Interactions in Patients With Myocardial Infarction.

BACKGROUND: Metabolic syndrome (MetS) is associated with worse prognosis in patients with myocardial infarction (MI). However, it is unclear how MetS in MI patients is associated with left atrial (LA) and left ventricular (LV) deformation. PURPOSE: To determine the effect of MetS on LA and LV deformation and atrioventricular interactions in MI patients. STUDY TYPE: Retrospective. POPULATION: One hundred eighty-one MI patients (73 MetS+ and 108 MetS-), 107 age- and sex-matched controls (49 MetS+ and 58 MetS-). FIELD STRENGTH/SEQUENCE: 3.0 T/balanced steady-state free precession (SSFP)/segmented phase-sensitive inversion recovery SSFP sequence. ASSESSMENT: LA strain and strain rates (reservoir, conduit, and active), left atrioventricular coupling index (LACI), and LV geometry and radial, circumferential and longitudinal global peak strains (PS) were compared among groups. STATISTICAL TESTS: Two-way analysis of variance, Spearman and Pearson's correlation coefficients, and multivariable linear regression analysis. P value <0.05 indicated statistical significance. RESULTS: Compared with controls, the MI patients with or without MetS showed impaired LA function (reservoir, conduit, and active) and LV deformation (radial, circumferential, and longitudinal PS) and higher LACI. The MetS+ group had lower LA reservoir and conduit function and LV deformation than MetS- group. The MetS-MI interaction was not statistically significant. Furthermore, multivariable linear regression showed that MetS was independently associated with LA and LV deformation (ß = -0.181 to -0.209) in MI patients; LA function was independently associated with LV circumferential PS (ß = 0.230 to 0.394) and longitudinal PS (ß = 0.189 to 0.420), and LA passive strain and strain rate were negatively associated with LV mass (ß = -0.178 and -0.298). DATA CONCLUSION: MetS may be associated with the LA and LV dysfunction in MI patients. Impaired LV deformation and LV hypertrophy are independently associated with LA dysfunction in MI patients, and the MI patients have higher LACI than controls, suggesting atrioventricular interaction alterations. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: 3.

Impact of T2DM on right ventricular systolic dysfunction and interventricular interactions in patients with essential hypertension: evaluation using CMR tissue tracking.

BACKGROUND: Previous studies reported that there was right ventricular (RV) systolic dysfunction in patients with hypertension. The aim of this study was to evaluate the impact of type 2 diabetes mellitus (T2DM) on RV systolic dysfunction and interventricular interactions using cardiac magnetic resonance feature tracking (CMR-FT) in patients with essential hypertension. METHODS AND METHODS: Eighty-five hypertensive patients without T2DM [HTN(T2DM -)], 58 patients with T2DM [HTN(T2DM +)] and 49 normal controls were included in this study. The biventricular global radial, circumferential and longitudinal peak strains (GRS, GCS, GLS, respectively) and RV regional strains at the basal-, mid- and apical-cavity, were calculated with CMR-FT and compared among controls and different patient groups. Backward stepwise multivariable linear regression analyses were used to determine the effects of T2DM and left ventricular (LV) strains on RV strains. RESULTS: The biventricular GLS and RV apical longitudinal strain deteriorated significantly from controls, through HTN(T2DM-), to HTN(T2DM +) groups. RV middle longitudinal strain in patient groups were significantly reduced, and LV GRS and GCS and RV basal longitudinal strain were decreased in HTN(T2DM +) but preserved in HTN(T2DM-) group. Multivariable regression analyses adjusted for covariates demonstrated that T2DM was independently associated with LV strains (LV GRS: ß = - 4.278, p = 0.004, model R2 = 0.285; GCS: ß = 1.498, p = 0.006, model R2 = 0.363; GLS: ß = 1.133, p = 0.007, model R2 = 0.372) and RV GLS (ß = 1.454, p = 0.003, model R2 = 0.142) in hypertension. When T2DM and LV GLS were included in the multiple regression analysis, both T2DM and LV GLS (ß = 0.977 and 0.362, p = 0.039 and < 0.001, model R2 = 0.224) were independently associated with RV GLS. CONCLUSIONS: T2DM exacerbates RV systolic dysfunction in patients with hypertension, which may be associated with superimposed LV dysfunction by coexisting T2DM and suggests adverse interventricular interactions.

[Extranodal Rosai-Dorfman Disease of Anterior Mediastinum: A Case Report].

A 28-year-old female patient was referred to and admitted in our hospital for presence of anterior mediastinal mass for 4 years. Enchanced chest computed tomography (CT) revealed an anterior mediastinal mass of soft-tissue density measuring 7.1 cm×3.8 cm with slight homogeneous enhancement after intravenous administration of contrast agent. The mass was clinically considered a thymoma. Then, surgical excision of anterior mediastinal mass was performed under general anesthesia. Postoperative histopathology revealed that there were foamy histiocyte clusters on the background of fibrous tissue hyperplasia and hyaline, with lymphoid hyperplasia, infiltration of plasma cells, and the presence of emperipolesis of lymphocytes and plasma cells in the tissue cells. Immunohistochemistry showed S100 protein (+), cluster of differentiation (CD) 68 (+), CD163 (+), immunoglobulin G4 (+), and CD1a (-). Eventually, confirmed diagnosis of extranodal Rosai-Dorfman disease was made. The patient showed no clinical symptoms and no recurrence was found on CT images over the 3-year followup. In clinical practice, this disease should be differentiated from other anterior mediastinal masses such as thymoma, lymphoma, and teratoma.

Carbonized biosorbent assisted matrix solid-phase dispersion microextraction for active compounds from functional food.

In this study, mangosteen peel based activated carbon was prepared and first applied as adsorbent in matrix solid-phase dispersion (MSPD) for simultaneously extraction of flavonoids from Dendrobium huoshanense prior to their separation and determination by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). The MSPD-UHPLC-Q-TOF/MS method was validated exhaustively. Good linearities (r2 ≥ 0.9929) were obtained for all target analytes. The limits of detection was in the range of 0.00387-0.159 µg/g. Satisfactory recoveries of six target compounds were between 80.02 and 99.49% and 85.32-99.86% for the low and high spiked level, respectively. Furthermore, relative to other common sorbent, the prepared mangosteen peel based activated carbon was less expensive and more environmentally-friendly. Consequently, the proposed method was a simple, efficient, low-cost, eco-friendly, time-saving and sensitive approach that could be successfully applied to the extraction and determination of flavonoids compounds in complex matrix.

Impact of gender on left ventricular deformation in patients with essential hypertension assessed by cardiac magnetic resonance tissue tracking.

Left ventricular (LV) myocardial strain impairment has been demonstrated in hypertension despite normal LV ejection fraction (LVEF); however, limited data exist on any difference in results between genders. The aim of this study was to investigate the impact of gender on LV deformation in patients with essential hypertension. This was a cross-sectional study, in which 94 patients (47 men and 47 women) with essential hypertension and 62 age- and gender-matched controls (31 men and 31 women) were enrolled. A 3.0 T/two-dimensional balanced steady-state free precession cine, late gadolinium enhancement was used. The LV endocardial and epicardial contours were drawn by radiologists, then LV volumes, mass, function, and myocardial strain, including peak global radial (GRS), circumferential (GCS), and longitudinal strain (GLS) were automatically calculated. Chi-square test, Student's t-test, general linear model analysis, univariate linear regression analysis, stepwise multivariate linear regression analysis, and intraclass correlation coefficient analysis were performed. Women had significantly higher magnitudes of LV GRS, GCS, and GLS than men in both patients and controls (all p < 0.05). In the overall patients, LV GLS was significantly reduced compared with controls (p < 0.05), while GRS and GCS were preserved (p = 0.092 and 0.27, respectively). Compared with their counterpart controls, LV GRS, GCS, and GLS (all p < 0.05) were significantly reduced in hypertensive men, while only GLS (p < 0.05) was reduced in hypertensive women. Male gender and its interaction with hypertension were associated with higher LV mass and volume, decreased LV GRS, GCS, and GLS compared with hypertensive women. Multivariate analyses revealed that gender and LVEF were independently associated with GRS, GCS, and GLS (all p < 0.001) in hypertension. LV deformation is significantly reduced in hypertension, and gender may influence the response of LV deformation to hypertension, with men suffering more pronounced subclinical myocardial dysfunction. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 3.

Modern microextraction techniques for natural products.

Natural product analysis has gained wide attention in recent years, especially for herbal medicines, which contain complex ingredients and play a significant clinical role in the therapy of numerous diseases. The constituents of natural products are usually found at low concentrations, and the matrices are complex. Thus, the extraction of target compounds from natural products before analysis by analytical instruments is very significant for human health and its wide application. The commonly used traditional extraction methods are time-consuming, using large amounts of sample and organic solvents, as well as expensive and inefficient. Recently, microextraction techniques have been used for natural product extraction to overcome the disadvantages of conventional extraction methods. In this paper, the successful applications of and recent developments in microextraction techniques including solvent-based and sorbent-based microextraction methods, in natural product analysis in recent years, especially in the last 5 years, are reviewed for the first time. Their features, advantages, disadvantages, and future development trends are also discussed.

The additive effects of type 2 diabetes mellitus on left ventricular deformation and myocardial perfusion in essential hypertension: a 3.0 T cardiac magnetic resonance study.

BACKGROUND: Type 2 diabetes mellitus (T2DM) increases the risks of heart failure and mortality in patients with hypertension, however the underlying mechanism is unclear. This study aims to investigate the impact of coexisting T2DM on left ventricular (LV) deformation and myocardial perfusion in hypertensive individuals. MATERIALS AND METHODS: Seventy hypertensive patients without T2DM [HTN(T2DM-)], forty patients with T2DM [HTN(T2DM+)] and 37 age- and sex-matched controls underwent cardiac magnetic resonance examination. Left ventricular (LV) myocardial strains, including global radial (GRPS), circumferential (GCPS) and longitudinal peak strain (GLPS), and resting myocardial perfusion indices, including upslope, time to maximum signal intensity (TTM), and max signal intensity (MaxSI), were measured and compared among groups by analysis of covariance after adjusting for age, sex, body mass index (BMI) and heart rate followed by Bonferroni's post hoc test. Backwards stepwise multivariable linear regression analyses were performed to determine the effects of T2DM on LV strains and myocardial perfusion indices in patients with hypertension. RESULTS: Both GRPS and GLPS deteriorated significantly from controls, through HTN(T2DM-), to HTN(T2DM+) group; GCPS in HTN(T2DM+) group was lower than those in both HTN(T2DM-) and control groups. Compared with controls, HTN(T2DM-) group showed higher myocardial perfusion, and HTN(T2DM+) group exhibited lower perfusion than HTN(T2DM-) group and controls. Multiple regression analyses considering covariates of systolic blood pressure, age, sex, BMI, heart rate, smoking, indexed LV mass and eGFR demonstrated that T2DM was independently associated with LV strains (GRPS: p = 0.002, model R2= 0.383; GCPS: p < 0.001, model R2= 0.472; and GLPS: p = 0.002, model R2= 0.424, respectively) and perfusion indices (upslope: p < 0.001, model R2= 0.293; TTM: p < 0.001, model R2= 0.299; and MaxSI: p < 0.001, model R2= 0.268, respectively) in hypertension. When both T2DM and perfusion indices were included in the regression analyses, both T2DM and TTM were independently associated with GRPS (p = 0.044 and 0.017, model R2= 0.390) and GCPS (p = 0.002 and 0.001, model R2= 0.424), and T2DM but not perfusion indices was independently associated with GLPS (p = 0.002, model R2= 0.424). CONCLUSION: In patients with hypertension, T2DM had an additive deleterious effect on subclinical LV systolic dysfunction and myocardial perfusion, and impaired myocardial perfusion by coexisting T2DM was associated with deteriorated LV systolic dysfunction.

Simultaneous separation and concentration of neutral analytes by cyclodextrin assisted sweeping-micellar electrokinetic chromatography.

An on-line cyclodextrin assisted sweeping-micellar electrokinetic chromatography (CD assisted sweeping-MEKC) was developed for the simultaneous separation and concentration of four neutral analytes (erianin, dendrophenol, naringenin and scoparone) in Dendrobium officinale Kimura et Migo (D. officinale). The D. officinale was directly determined by this on-line stacking method after simple extraction and dilution. The optimized background solution (BGS) was 50 mM phosphoric acid (PA) containing 100 mM SDS and 30% (v/v) methanol. The best separation and concentration performance of analytes dissolved in 90 mM CD and 100 mM PA was achieved in a short analysis time when injected at 50 mbar for 100 s. Compared with conventional sweeping-MEKC and MEKC method, significant improvement in enrichment efficiency was achieved by using this proposed method. A series of validation studies of the present method was performed under the optimal conditions. Good linearities were obtained with the correlation coefficients in the range of 0.994-0.999, the detection limits were ranged from 13 to 40 ng/mL. Sensitivity enhancement factors (SEFs) were in the range of 28.5-46.8 compared with traditional injection (injection time 3 s). Therefore, the proposed method was successfully applied for the separation and concentration of neutral analytes in real samples.

Vesicle based ultrasonic-assisted extraction of saponins in Panax notoginseng.

A simple and effective vesicle based ultrasonic-assisted extraction (UAE) method was developed for extraction of active compounds in functional food. The target analytes were determined by ultra-high performance liquid chromatography with ultraviolet detector. Surfactant vesicle was adopted as extraction solvent. Different operating conditions including the type and concentration of vesicle, extraction time and solid to liquid ratio were investigated by single-factor experiments and response surface methodology. Optimized experimental conditions were 1% (w/v) of DTAB/SDS vesicle, 20 min of extraction time and 160 mg/mL of solid to liquid ratio. The proposed method provided good linearity in the linear range of 10-1000 µg/mL with regression coefficients larger than 0.999, low limits of detection of 27.64-55.67 ng/mL, good precision with relative standard deviations below 0.35%, and satisfactory recoveries of 83.84-90.92% for tested saponins. Consequently, the proposed vesicle based UAE method was well suited for the extraction of saponins in Panax notoginseng.

[Risk Factors for Adverse Aortic Remodeling in Post-TEVAR Patients with Acute Stanford B Aortic Dissection].

OBJECTIVES: To assess morphological changes of distal aorta and the risk factors for adverse aortic remodeling inpost-TEVAR（thoracic endovascular aortic repair） patients with acute Stanford B aortic dissection. METHODS: We retrospectively investigated the patients who underwent TEVAR for a type B dissection between October 2005 and December 2015. CT angiogram (CTA) was obtained for each patients preoperatively, postoperatively and during the post-operational follow-up. Based on Criadol partition principle, we divided the aorta into descending thoracic aorta area, suprarenal abdominal aorta area, infrarenal abdominal aorta area and iliac artery area, and evaluated the distribution of aortic tears and the form of true and false lumen in different aortic partition. Univariate and multivariate logistic regression analyses were used to analyze the risk factors affecting distal aortic remodeling. RESULTS: Of 216 patients (mean follow-up (3.9±2.1) years) who were regularly followed up in our center, 47 patients (21.8%) occurred adverse remodeling in distal aorta. Univariate logistic regression indicated that abnormal aortic wall structure (Marfan's syndrome) and patent false lumen (existence of distal tears, decreased complete false lumen thrombosis) were associated with distal aortic adverse remodeling. Multivariate logistic regression showed that more tears in descending thoracic aorta area ( OR=1.36, 95% CI=1.12-1.58, P=0.005) and less tears in infrarenal abdominal aorta area ( OR=0.49, 95% CI=0.22-0.71, P<0.001) were independent risk factors affecting remodeling in distal aorta after TEVAR. CONCLUSIONS: Aortic wall structure abnormalities, a patent false lumen, more tears in descending thoracic aorta area, less tears in infrarenal abdominal aorta area are independent risk factors for adverse aortic remodeling in post-TEVAR patients with acute Stanford B aortic dissection.

Ecofriendly microwave-assisted reaction and extraction of bioactive compounds from hawthorn leaf.

INTRODUCTION: The main active components in hawthorn leaves possess various biological activities such as anti-inflammatory, antioxidant, and hypolipidemic effects. Therefore, it is necessary to develop an effective and reliable extraction method to extract these active compounds from hawthorn leaves. OBJECTIVE: To establish a simple, rapid, and sensitive method for extraction and determination of polyphenolic compounds from hawthorn leaves. METHODS: In this study, a microwave-assisted reaction and extraction (MARE) combined with ultra-high-performance liquid chromatography with ultraviolet detector method was established to extract and determine the polyphenolic compounds in hawthorn leaves. The solid reagent aqueous solutions were applied as extraction solvents, preventing the use of organic solvents. The target analytes were identified by quadrupole time-of-flight tandem mass spectrometry. Several experimental parameters that can significantly affect the extraction efficiency were evaluated and optimised. RESULTS: The optimal conditions were as follows: 0.1 g of sodium carbonate was used as solid reagent, the amount of sodium borate was set at 0.01 g, extraction time was 10 min, extraction temperature was set at 50°C, pH value was adjusted to 7. The validation experiments demonstrated that the method had high sensitivity with the limits of detection in the range 26.5-37.7 ng/mL. The average recoveries ranged from 80.22% to 93.27%. CONCLUSION: In this work, the proposed MARE method was successfully applied to extract and determine polyphenolic compounds in hawthorn leaf samples. Compared with other reported methods, the present method was faster, greener, and more sensitive.

Carbon molecular sieve based micro-matrix-solid-phase dispersion for the extraction of polyphenols in pomegranate peel by UHPLC-Q-TOF/MS.

A rapid, simple, and efficient sample extraction method based on micro-matrix-solid-phase dispersion (micro-MSPD) was applied to the extraction of polyphenols from pomegranate peel. Five target analytes were determined by ultra-HPLC coupled with Q-TOF/MS. Carbon molecular sieve (CMS) was firstly used as dispersant to improve extraction efficiency in micro-MSPD. The major micro-MSPD parameters, such as type of dispersant, amount of dispersant, grinding time, and the type and the volume of elution solvents, were studied and optimized. Under optimized conditions, 26 mg of pomegranate peel was dispersed with 32.5 mg of CMS, the grinding time was selected as 90 s, the dispersed sample was eluted with 100 µL of methanol. Results showed that the proposed method was of good linearity for concentrations of analytes against their peak areas (coefficient of determination r2 > 0.990), the LOD was as low as 3.2 ng/mL, and the spiking recoveries were between 88.1 and 106%. Satisfactory results were obtained for the extraction of gallic acid, punicalagin A, punicalagin B, catechin, and ellagic acid from pomegranate peel sample, which demonstrated nice reliability and high sensitivity of this approach.

Rapid microwave-assisted dispersive micro-solid phase extraction of mycotoxins in food using zirconia nanoparticles.

Mycotoxins are a group of secondary fungi metabolites present in foods that cause adverse effects in humans and animals. The objective of this study was to develop and validate a reliable and sensitive method to determine the presence of fumonisin B1, aflatoxin B1, ochratoxin B, T-2 toxin, ochratoxin A and zearalenone. A rapid, effective process, which involves microwave-assisted dispersive micro-solid phase extraction (MA-d-µ-SPE), has been proposed for the extraction and detection of 6 mycotoxins in peach seed, milk powder, corn flour and beer sample matrixes, for subsequent analysis by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Several experimental parameters (type of dispersant, concentration of dispersant, vortex time, type of desorption solvent and pH) affecting the extraction efficiency were systematically studied and optimized. The optimum extraction conditions involved immersing 2.5 µg/mL of nano zirconia (as dispersant) in a 5 mL sample solution. After 2 min of extraction by vigorous shaking, the target analytes were desorbed by 100 µL of chloroform at pH 4.5. The results indicated good linearity in the range of 0.0074-3.6 µg/mL (r ≥ 0.9982), low limits of detection (0.0036-0.033 µg/kg for solid samples and 0.0022-0.017 ng/mL for beer), acceptable reproducibility (relative standard deviation (RSD%) 2.08-2.76% for retention time and 3.51-4.59% for peak area, n = 3), and satisfactory spiked recoveries (84.27-104.96%) for studied mycotoxins in sample matrixes, which demonstrated that MA-d-µ-SPE coupled with UHPLC-Q-TOF/MS is a useful tool for analysis of multi-mycotoxin.

Crown ether microfunctionalized carbon nanotubes for dispersive micro-solid-phase extraction of sudan dyes and their metabolites.

In this study, dispersive micro solid phase extraction (DMSPE) combined with ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry method was established to extract and determine sudan dyes and their metabolites in real samples. The crown ether microfunctionalized multi-walled carbon nanotubes (MWCNTs) was applied as the sorbent in DMSPE procedure. Several experimental parameters that can effect the extraction performance of the DMSPE method were investigated separately by a univariate method. The validation data showed that the limits of detection were in the range of 0.084-13.13 µg/kg, the mean recoveries were ranged from 80.15 to 103.58% for six samples. Compared with other published methods, the proposed method was more effective, more time-saving and more eco-friendly. Finally, the developed method was successfully applied to enrich and detect sudan dyes and their metabolites in real samples.

Miniaturized solid-phase extraction of macrolide antibiotics in honey and bovine milk using mesoporous MCM-41 silica as sorbent.

A simple and effective method of miniaturized solid-phase extraction (mini-SPE) was developed for the simultaneous purification and enrichment of macrolide antibiotics (MACs) (i.e. azithromycin, clarithromycin, erythromycin, lincomycin and roxithromycin) from honey and skim milk. Mesoporous MCM-41 silica was synthesized and used as sorbent in mini-SPE. Several key parameters affecting the performance of mini-SPE procedure were thoroughly investigated, including sorbent materials, amount of sorbent and elution solvents. Under the optimized condition, satisfactory linearity (r2 > 0.99), acceptable precision (RSDs, 0.3-7.1%), high sensitivity (limit of detection in the range of 0.01-0.76 µg/kg), and good recoveries (83.21-105.34%) were obtained. With distinct advantages of simplicity, reliability and minimal sample requirement, the proposed mini-SPE procedure coupled with ultrahigh performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry could become an alternative tool to analyze the residues of MACs in complex food matrixes.

Pyridinium ionic liquid-based liquid-solid extraction of inorganic and organic iodine from Laminaria.

A simple, green and effective extraction method, namely, pyridinium ionic liquid- (IL) based liquid-solid extraction (LSE), was first designed to extract the main inorganic and organic iodine compounds (I-, monoiodo-tyrosine (MIT) and diiodo-tyrosine (DIT)). The optimal extraction conditions were as follows: ultrasonic intensity 100W, IL ([EPy]Br) concentration 200mM, extraction time 30min, liquid/solid ratio 10mL/g, and pH value 6.5. The morphologies of Laminaria were studied by scanning electron microscopy and transmission electron microscopy. The recovery values of I-, MIT and DIT from Laminaria were in the range of 88% to 94%, and limits of detection were in the range of 59.40 to 283.6ng/g. The proposed method was applied to the extraction and determination of iodine compounds in three Laminaria. The results showed that IL-based LSE could be a promising method for rapid extraction of bioactive iodine from complex food matrices.

Rapid ultrasonic and microwave-assisted micellar extraction of zingiberone, shogaol and gingerols from gingers using biosurfactants.

Two kinds of extraction methods ultrasonic-assisted micellar extraction (UAME) and microwave-assisted micellar extraction (MAME) coupled with ultra-high performance liquid chromatography with ultraviolet detector (UHPLC-UV) were developed and evaluated for extraction and determination of zingerone, 6-gingerol, 8-gingerol, 6-shogaol and 10-gingerol in Rhizoma Zingiberis and Rhizoma Zingiberis Preparata. A biosurfactant, hyodeoxycholic acid sodium salt, was used in micellar extraction. Several experimental parameters were studied separately by a univariate method. The result indicated that the MAME was more efficient than UAME. The optimal conditions of MAME were as follows: 100mM of hyodeoxycholic acid sodium salt was used as surfactant, the irradiation time was set at 10s and the extraction temperature was set at 60°C. The validation results indicated that the limits of detection were in the range of 3.80-8.11ng/mL. The average recoveries were in the range of 87.32-103.12% for the two samples at two spiking levels. Compared with other reported methods, the proposed MAME-UHPLC-UV method was more effective, quicker (10s) and more eco-friendly.

Graphene nanoplatelets based matrix solid-phase dispersion microextraction for phenolic acids by ultrahigh performance liquid chromatography with electrochemical detection.

A simple, rapid and eco-friendly approach based on matrix solid-phase dispersion microextraction (MSPDM) followed by ultrahigh performance liquid chromatography coupled with electrochemical detection (UHPLC-ECD) was presented for the microextraction and determination of six phenolic acids in a plant preparation (Danshen tablets). The parameters that influenced the extraction performance of phenolic acids were investigated and optimized. The optimal MSPDM conditions were determined as follows: sorbent, using graphene nanoplatelets with sample/sorbent ratio of 1:1, grinding time set at 60 s, and 0.2 mL of water as elution solvent. Under the optimum conditions, the validation experiments indicated that the proposed method exhibited good linearity (r2 ≥ 0.9991), excellent precision (RSD ≤ 4.57%), and satisfactory recoveries (82.34-98.34%). The limits of detection were from 1.19 to 4.62 ng/mL for six phenolic acids. Compared with other reported methods, this proposal required less sample, solvent and extraction time. Consequently, the proposed method was successfully used to the extraction and determination of phenolic acids in Danshen tablets.

Microwave-assisted micellar extraction of organic and inorganic iodines using zwitterionic surfactants.

Zwitterionic surfactant, used as extractant in microwave-assisted extraction (MAE) was investigated for the first time to extract organic and inorganic iodines from kelp samples. Optimized conditions for the MAE were 200W of microwave irradiation power, 100°C of extraction temperature, 10min of microwave irradiation time, 1g of sample, and 20mL of solvent volume. Ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was used for the quantitative and qualitative analyses of the iodines. Under the optimum experimental conditions, KI, MIT and DIT were identified in kelp samples, the limits of detection of these analytes were ranged between 3.39 and 6.31ng/mL. The recoveries for spiked samples obtained from different areas were all higher than 92.48%. Compared with the ultrasound-assisted extraction, the proposed method is faster and more effective. Thus, the combination of zwitterionic surfactant-MAE and UHPLC-Q-TOF/MS made up a simple, rapid and effective approach for extraction and determination of iodine compounds in complex seaweed materials.

Analysis of phenolic acids by ionic liquid-in-water microemulsion liquid chromatography coupled with ultraviolet and electrochemical detector.

An environmentally friendly ionic liquid-in-water (IL/W) microemulsion was established and applied as mobile phase in microemulsion liquid chromatography (MELC) with ultraviolet (UV) detection or electrochemical detector (ECD) for analysis of phenolic compounds in real samples. The optimal condition of the method was using the best composition of microemulsion (0.2% w/v [HMIM]PF6, 1.0% w/v SDS, 3.0% w/v n-butanol, 95.8% v/v water, pH 2.5) with UV detection. The validation results indicated that the method provided high degree of sensitivity, precision and accuracy with the low limit of detections ranged from 17.9-238ng/mL, satisfactory mean recovery values in the range of 80.1-105% and good linearity (r2>0.9994). Additionally, this method exhibited high selectivity and resolution for the analytes and was more eco-friendly compared with traditional MELC method. Consequently, the established IL/W MELC method was successfully applied to simultaneously separate and determine target compounds in Danshen sample and its preparation.